The present invention relates generally to a stator for use in a brushless motor. More particularly, the invention relates to a stator which is compact in size and decreases soldering steps thereby improving a yield rate.
There has been known a conventional stator for use in a brushless motor shown in FIGS. 1A, 1B and 1C. More specifically, FIG. 1A is a front view of a conventional stator, FIG. 1B is a side view and FIG. 1C is a rear view of the stator.
The conventional stator is provided with a stator yoke 1, a first printed substrate 2 which is fixedly mounted on a front surface of the stator yoke 1 in such a manner that the substrate 2 faces a rotor of the motor, and a second printed substrate 3 which is fixedly mounted on a rear surface of the stator yoke 1. As shown in FIG. 1A, both a plurality of drive coils 4 for rotating the rotor of the motor and a plurality of hall elements 5 for detecting a rotational position of the rotor are mounted on the first printed substrate 2 and electrically connected thereto. A group of drive circuits 6 is disposed on the second printed substrate 3 and electrically connected thereto.
In the conventional stator shown in FIGS. 1A, 1B and 1C, six drive coils 4 and three hall elements 5 are utilized thereby constituting a three-phase drive system. The first printed substrate 2 and second printed substrate 3 are electrically connected to and communicated with each other through a plurality of copper wires 7. The copper wires 7 are insulated by a film 8 at an edge portion of the stator. Both ends of each of the drive coils 4 are connected to respective land portions 9 of the first printed substrate 2.
The conventional stator thus constructed necessitates eleven copper wires 7 in total because three wires are required for the drive coils 4 and eight wires are required for the hall elements 8. These eleven wires 7 are gathered in one portion on the stator thereby raising a problem in that a large range is necessary to be provided both on the first and second printed substrates 2 and 3, so that the size of the stator would be disadvantageously increased.
Moreover, many soldering steps are required for assembling the stator, for example, soldering steps for connecting the land portion 9 to a pattern of the first printed substrate 2, for connecting the pattern of the first printed substrate 2 to the copper wires 7, and for connecting the copper wires 7 to a pattern of the second printed substrate 3.